Dogs can get a Lyme disease vaccine. Why can’t humans?

It’s the season for tick bites. Each year, at least 300,000 people contract Lyme disease and about 10 to 15 percent report stubborn, long-lasting symptoms like achy joints, fatigue and memory lapses despite treatment. What are the mysteries of Lyme, and why is there no effective vaccine on the market for humans? Science correspondent Miles O’Brien reports.